Bill Cosby has been convicted of drugging and sexually assaulting a woman.

A jury outside Philadelphia convicted the Cosby Show star of three counts of aggravated indecent assault today. The guilty verdict came less than a year after another jury was deadlocked on the charges.

Cosby was charged with violating Temple University employee Andrea Constand at his suburban Philadelphia home in 2004.

His lawyer called Constand a "con artist" who levelled false accusations against Cosby so she could sue him.

Cosby could get up to 10 years in prison on each of the counts.

The comedian stood up and reacted angrily after jurors left the courtroom. He used an expletive to refer to District Attorney Kevin Steele, who was arguing to revoke Cosby's bail. Cosby shouted: "I'm sick of him."

Bill Cosby arrives at court today. Picture: AP

The judge ruled that Cosby will remain free pending sentencing.

Judge Steven O'Neill told the panel of seven men and five women that it was "an extraordinarily difficult case" and said the jurors "sacrificed in the service of justice".

After the verdict, Cosby's lawyer said the "fight is not over" and that Cosby will appeal against his conviction.

Cosby said nothing to reporters but acknowledged the crowd on the courthouse steps, then gave a thumbs-up as his car pulled away.

A lawyer for some of his accusers said "justice has been done" after the comedian's conviction.

Gloria Allred, who represents three of the five additional accusers who testified that Cosby drugged and molested them, said her clients are grateful to the jury for seeing past "his defence attorney's lies".

Janice Baker-Kinney, who alleges he drugged and raped her in 1982, said she is relieved "this toxic chain of silence has been broken" and the women can move forward "with heads held high".

Dozens of women have come forward in recent years to say he drugged and assaulted them. Five of the other accusers testified against him at the retrial.

The panel of seven men and five women reached a verdict after deliberating for 14 hours over two days, vindicating prosecutors' decision to retry the 80-year-old after his first trial ended with a hung jury less than a year ago.

Ms Constand, 45, a former Temple women's basketball administrator, told jurors that Cosby knocked her out with three blue pills he called "your friends" before attacking her.

It was the only criminal case to arise from a barrage of allegations from more than 60 women who said the former TV star drugged and molested them over a span of five decades.

"The time for the defendant to escape justice is over," prosecutor Stewart Ryan said in his closing argument. "It's finally time for the defendant to dine on the banquet of his own consequences."

Another prosecutor, Kristen Feden, said Cosby was "nothing like the image that he played on TV" as sweater-wearing, wisdom-dispensing father of five Dr Cliff Huxtable on The Cosby Show.

Cosby's retrial took place against the backdrop of #MeToo, the movement against sexual misconduct that has taken down powerful men in rapid succession, among them Harvey Weinstein, Matt Lauer, Kevin Spacey and Senator Al Franken.

The jurors all indicated they were aware of #MeToo but said before the trial they could remain impartial. Cosby's lawyers slammed #MeToo, calling Cosby its victim and likening it to a witch hunt or a lynching.

After failing to win a conviction last year, prosecutors had more courtroom weapons at their disposal for the retrial.

The other accusers' testimony helped move the case beyond a he-said, she-said, allowing prosecutors to argue that Cosby was a menace to women long before he met Ms Constand. Only one other accuser was permitted to testify at Cosby's first trial.

Andrea Constand.

Cosby's new defence team, led by Michael Jackson lawyer Tom Mesereau, launched a highly aggressive attack on Constand and the other women.

Their star witness, a long-time Temple employee, testified that Ms Constand once spoke of setting up a prominent person and suing. Ms Constand sued Cosby after prosecutors initially declined to file charges, settling with him for nearly $3.4m over a decade ago.

"You're dealing with a pathological liar," Mr Mesereau told the jury.

But Cosby himself had long ago confirmed sordid revelations about drugs and extramarital sex.

In a deposition he gave over a decade ago as part of Ms Constand's lawsuit, Cosby acknowledged he had obtained quaaludes to give to women he wanted to have sex with, "the same as a person would say, 'Have a drink.'" The sedative was a popular party drug before the US banned it more than 30 years ago.

Cosby also acknowledged giving pills to Ms Constand before their sexual encounter. But he identified them as the over-the-counter cold and allergy medicine Benadryl and insisted they were meant to help her relax.

The entertainer broke racial barriers as the first black actor to star in a network show, I Spy, in the 1960s. He created the top-ranked Cosby Show two decades later.